<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>主元素与子元素（伪元素）之间的重叠关系</title>
		<style>
			div, div::before, div::after{
				width: 10em;
				height: 10em;
				border-radius: 50%;
			}
			div{
				font-size: 10px;
				margin: 4em;
				position: relative;
				background-color: lightgreen;
				z-index: auto;
			}
			div::after, div::before{
				content: '';
				position: absolute;
				top: 5em;
			}
			div::before{
				background-color: moccasin;
				left: 3em;
				z-index: -1;
			}
			div::after{
				background-color: orange;
				right: 3em;
				z-index: -2;
			}
		</style>
	</head>
	<body>
		<div></div>
	</body>
</html>
